Disconnecting switch



Jan. 9, 1945. K A, HAWLEY 2,366,784

DISCONNECTING SWITCH Filed Feb. 4, 1943 2 Sheets-'Sheet 1 Jan. 9, 1945. K A HAWLEY 2,366,784

DISCONNECTING SWITCH Filed Feb. 4, 1943 2 Sheets-Sheet 2 MSS Patented Jan. 9, 1945 DISCONNECTING SWITCH Kent A. Hawley, Lansdowne, Pa., assigner to Electric Power Equipment Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application February 4, 1943, Serial No. 474,733 i (Cl. 20G-48) Claims.

This invention relates to disconnecting switches and more particularly to the construction of aswitch wherein the switch blades are carried by a central rotating shaft, rotation of which provides a double break in the lines between the ends of opposed pairs of contacts.

Animportant object of the invention is the provision in a switch of this character of an arrangement in which the shaft is of itself of insulating material and is interposed between ycoacting contacts when the shaft is in the open position, thereby making the effective striking distance between the line contacts much greater than it would be ordinarily and enabling the structure to be compactly arranged as regards the spacing between such contacts.

A-further object of the invention is the provision in a structure of this character wherein the contacts are themselves so shielded that the effective striking distance 4between adjacent contacts at the same side of the shaft is effectively increased thereby enabling a more compact arrangement of such contacts in a direction axial to the shaft and furthermore enabling a reduction in the normal necessary distance between end contacts and the adjacent end walls of the switch casing.

A still further object of the invention is the provision of a blade structure facilitating mounting and centering of the blades in the shaft.

Another object of the invention is the provision of a switch of this character which permits visual determination of the blade .position at all times,

These and other objects I attain `by the construction shown in the accompanying drawings wherein, for the purpose of illustration, I have shown a preferred embodiment of my invention and wherein:

Figure 1 is a side elevation partially in vertical section cfa disconnecting switch constructed in accordance with my invention;

Figure 2 is a characteristic vertical sectional view through the switch at any aligned pair of contacts, the switch being in the closed position;

Figure 3 is a fragmentary sectional plan view taken on line 3-3 of Figure l; and

`Figure 4 is an enlarged exploded view in perspective showing certain elements of the switch mechanism` Referring now more particularly to the draw- I6, the bearing I4 being preferably of the cap type and the bearing I5 permitting passage of an end portion of shaft I6, to which is attached a suitable operating handle generally designated at il. The operating handle, as is customary in switches of this character, may be provided with a'safety latchy as generally designated at I8.

The shaft IE is of insulating material, preferably a ceramic material and is at longitudinally spaced points .provided with a plurality of parallel transverse diametral bores I9, which bores pass centrally through truncated spherical enlargements of the shaft. Outwardly of each end enlargement 2D the shaft is preferably increased in diameter as at 2| and the inner ends of these portions of increased diameter are prof vided with circumferential flanges 22, the purpose of which will presently appear.

The outer ends of the bores I9 have the form of countersunk recesses 23 and within each of the bores is a blade 24. The blades 24 each comprise a central blade element supporting and positioning unit, consisting of a thin plate 25 having at opposite ends thereof centrally located longitudinally projecting studs 2B. Arranged at opposite sides of this plate are blade elements 2'I of any suitable conducting material. Arranged outwardly of the blade elements 21 are springs 28, the mutual conformation of the outer faces of the blade and the springs being such that contact between the blade and springs normally occurs only at or adjacent the ends of the spring elements. In the present instance, the outer faces of the blade elements 21 are shown as flat whereas the springs themselves are bowed with the ment. The plate 25, blade velements 21 and springs 28 are held in assembled relation by through-bolts 29' which are of such length as to permit a small gap, say of an inch, between the outer faces of the blade elements and the confronting surfaces of the springs at the through-bolts. This arrangement will permit the blade elements to separate when engaging the contacts and maintain a spring engagement with the contacts after the engagement is completed. These assemblages are maintained in ,position in the bores by mounting upon the studs 2G elongated washers 3D, the ends of which set upon the bases of recesses 23. The longitudinal position of the plate 25 in the bore i9 may be determined by adjustment of the retaining and locknut assemblies 3l upon the studs. Shaft I6 may n be formed in any suitable manner, but for purposes of economy, it is however preferred that the main body of the shaft lbe formed by casting by which method hollow pillars 32 will be cast into the shaft to complete the bores I9 housing the blades.

The end and upper and lower walls of the switch casing may be metallic and in the upper and lower walls are arranged mounting plates 33 bearing insulators 34 carrying the switch contacts 35. The insulators 34 are preferably of the ceramic type and have each at the inner end thereof a bowl-shaped hood 36, the rim portion of which projects well inwardly of the inner extremity of the supported contact 35, which hood embraces the spherical enlargement of shaft i6 through which the associated blade member 24 is directed. Due to the fact that the rims of the hoods 3G project well inwardly of the inner ends of the contacts 35, the effective air gap between adjacent contact elements at the same side of the shaft is materially increased in length thereby permitting the contacts 35 themselves to be much more closely arranged than would otherwise be possible. Enlargement of the shaft I6, as at 2 I, and the provision of the circumferential anges 22, which `are arranged immediately outwardly of the endmost insulators 34, increases the effective air gap between the endmost contacts 35 and the earth as represented by the metallic end walls of the casing. Utilization of a transparent insulating material in the formation of the side walls I3 enables, in addition to permitting visual determination of the switch position at all times, permits disposition of these side walls in immediate proximity to the insulators 34.

It will be obvious that the construction described provides a disconnecting switch in which safe isolation of the contacts may be had in an extremely compact and readily manufacturable construction. Since the structure is obviously capable of considerable modification without departing from the spirit of my invention, I do not wish to be understood as limiting myself thereto except as hereinafter claimed.

I claim:

l. A disconnecting switch of the type where-in there are pairs of opposed contacts and rotatable blades disposed between said contacts to connect and disconnect the contacts of the pairs, a shaft composed of insulating material supporting said blades, said shaft being of a size such that in the off position of the blades the shaft presents an insulating surface of considerable width as compared to the size of the contacts whereby to increase the effective air gap between the contacts, insulators supporting said contacts, said insulators each comprising a bowl-shaped hood surrounding the inner end of the Contact and projecting well beyond the inner end of the contact toward said shaft whereby to increase the effective air gap between adjacent contacts at ie same side of the shaft.

2. A disconnecting switch of the type wherein there are pairs of opposed contacts and rotatable blades disposed between said contacts to connect and disconnect the contacts of the pairs. a shaft composed of insulating material supporting said blades, insulators supporting said contacts, said insulators each comprising a bowl-shaped hood surrounding the inner end of the contact and projecting well beyond the inner end of the contact toward said shaft whereby to increase the effective air gap between adjacent contacts at the same side of the shaft.

3. Adisconnecting switch of the type wherein there are pairs of opposed contacts and rotatable blades disposed between said contacts to connect and disconnect the contacts of the pair, a shaft supporting said blades, said shaft being composed of insulating material having enlargements disposed between each pair of opposed contacts and in which said blades are mounted whereby the effective air gap between the contacts of the pairs is materially increased when the blades are moved to the disconnecting position, insulators supporting said contacts, said insulators each comprising a bowl-shaped hood surrounding the inner end of the contact and projecting well beyond the inner end of the contact toward said shaft whereby to increase the effective air gap between adjacent contacts at the same side of the shaft.

4. A device as claimed in claim 1 wherein the switch includes a casing having upper and lower walls in which said insulators are mounted, said casing further including transparent insulating side walls arranged in close proximity tothe insulators.

5. A device as claimed in claim 1 wherein the shaft outwardly of the endmost insulators is enlarged in diameter and projects outwardly beyond the rims of said bowl-shaped hoods whereby to increase the effective air gap between the endmost contacts and supports for the ends of said shaft.

6. A device as claimed in claim 1 wherein the switch includes a casing having upper and lower walls in which said insulators are mounted, said casing further including transparent insulating side walls arranged in close proximity to the insulators, the shaft outwardly of the endmost insulators being enlarged in diameter and projecting outwardly beyond the rims of said bowlshaped hoods whereby to increase the effective air gap between the endmost contact-s and supports for the ends of said shaft.

7. A device as claimed in claim 2 wherein the switch includes a casing having upper and lower' walls in which said insulators are mounted, said casing further including transparent insulating side walls arranged in close proximity to the insulators.

8. A device as claimed in claim 3 wherein the switch includes a casing having upper and lower walls in which said insulators are mounted, said casing further including transparent insulating side walls arranged in close proximity to the insulators.

9. A device as claimed in claim 2 wherein the switch includes a casing having upper and lower walls in which said insulators are mounted, said casing further including transparent insulating side walls arranged in close proximity to the insulators, the shaft outwardly of the endmost insulators being enlarged in diameter and projecting outwardly beyond the rims of said bowlshaped hoods whereby to increase the effective air gap between the endmost contacts and supports for the ends of said shaftl0. A device as claimed in claim` 6 wherein the switch includes a casing having upper and lower walls in which sair insulators are mounted, said casing further including transparent insulating side walls arranged in close proximity to the insulators, the shaft outwardly of the endmost irisulators being enlarged in diameter and projecting outwardly beyond the rims of said bowlshaped hoods whereby to increase the effective air gap between the endmost contacts and supports for the ends of said shaft.

KENT A. HAWLEY. 

